湍流强度对大气传输光束的相位特性及其相位校正物理极限的影响  

Effect of Turbulence Strength on Phase Characteristics and Physical Limit of Phase Correction of Laser Beams in Turbulence

作　　者：韩开[1] 张晓欣[1] 付福兴[1] 贺也洹[1] 张彬[1] 

机构地区：[1]四川大学电子信息学院,四川成都610064

出　　处：《激光与光电子学进展》2013年第1期80-86,共7页Laser & Optoelectronics Progress

基　　金：中国科学院自适应光学重点实验室基金(LAOF201101);四川大学优秀青年学者科研基金资助课题

摘　　要：运用相位屏近似法计算模拟了激光束通过大气湍流的光场分布。从高频相位比例和相位不连续点数目等角度对畸变光束的相位特性进行了分析,进而利用考虑到变形镜驱动器间交联耦合的高通滤波方法模拟自适应系统对畸变波前的校正作用,建立了畸变光束的相位校正物理极限的预估模型,定量分析了湍流强度和传输距离对校正极限的影响。研究结果表明:在一定范围内,随着湍流强度的增强及传输距离的增大,畸变波前中高频相位比例明显增加,相位不连续点数目也逐渐增多;激光束通过大气湍流后,其相位校正的效果主要受畸变光束连续相位中的高频相位比例以及相位不连续点数目的共同影响,畸变波前中高频相位比例越大,相位不连续点的数目越多,相位校正效果也越差。Using phase-screen approximation, the field distribution of laser beams propagating through atmospheric turbulence is calculated and simulated. The wavefront phase of the distorted beam in turbulence is also analyzed in terms of the high-frequency phase proportion and the number of branch points. Furthermore, considering the coupling between deformable mirror actuators, the model for estimating the physical limit of phase correction is built up by using the method of high-pass filtering including a smoothing factor of mirror actuator. The influence of turbulence intensity and propagation distance on the physical limit of phase correction is analyzed quantitatively. The results show that in a certain range, the proportion of high frequency in distorted phase increases obviously and the number of branch points grows gradually with the increase of turbulence intensity and propagation distance; the correction effect of laser beams in turbulence would be influenced mainly by the proportion of high-frequency in distorted phase and the number of branch points, and the greater the proportion of high frequency phase or the more the number of branch points is, the worse the correction effect of adaptive system would be.

关 键 词：自适应光学 大气湍流 高频相位 相位不连续点 校正效果 

分 类 号：O439[机械工程—光学工程]